Process of manufacturing adhesives.



UNITED STATES PATENT QFFTQE.

WALTER ALEXANDER, OF NEW YORK, N. Y., ASSIGNOR T0 NATIONAL GUM & MICACOMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF MANUFACTURING ADHESIVES.

No Drawing.

To all whom it may concern Be it known that I, WALTER ALEXANDER, acitizen of the United States, residing in the borough of Manhattan,city, county, and State of New Yorln have invented certain new anduseful Improvements in Processes of Manufacturing Adhesives, of whichthe following is a specification.

My invention has reference to improvements in the manufacture ofadhesives, and is-directed more particularly to an improved, rapidprocess for the production of a dry product. Heretofore, it has .been acommon practice to mix the several ingredients with a relatively largequantity of water, and, when a mass of thin, or jelly-like consistencycontaining a relatively large amount of water has been attained, tospread the mixture into trays or on nets in the form of films or layersfor drying. Numerous disadvantages have attended this method, however;among which may be mentioned the great difficulty in obtaining asufficiently rapid drying of the jelly, due to the large quantity ofwater present. The moist jelly being extremely sensitive to thedestructive action of bacteria and molds, large quantities are oftenspoiled before complete evapo ration Has taken place. This is especiallytrue in summer and damp weather, when, owing to the unfavorable climaticconditions, it has been found practically impossible to dry the jellyrapidly enough to prevent spoiling, and hence, necessary to abandon themanufacture of gelatinous adhesives atsuch times. It is my purpose toobviate these difficulties, and, at the same time. to obtain a vastlyincreased output, by reducin to a minimum the time heretofore requiredin drying the product. I have discovered that, by subjecting the severalingredients to the action of a mixing machine of high power, similar tothe type often used for making dough, it is possible to reduce to aminimum the initial quantity of water required for the formation of themixture, and after thoroughly mixing the'co'mponent parts inthe machine,to obtain a very highly concentrated product by pressing it out intothin sheets, as by passing the mixture through a pair of pressure rolls.The bulk of the moisture remaining in the product will be expelled bythe action of the rolls, so that drying takes place in a comparativelyshort time, the actual time consumed de- Speoification of LettersPatent.

Application filed December 6, 1913.

Patented Aug. 141, 1917.

Serial No. 804,990.

pending upon the thickness of the sheet obtained.

Acharacteristic of my process is that the required ingredients are mixedin the presence of the smallest practicable quantity of water which maybe used and still permit the necessary interaction and intermingling ofthe ingredients. Such an operation is made possible by utilizing amixing machine which is sufiiciently heavy and powerful to handle astiff and essentially non-fluid mass. The mixing process thereforecommences with a maximum of dry material. During this processevaporation is promoted mechanically by the mere stirring effect of theblades or agitators. As the ingredients become more and-more intimatelymixed, the presence of a solvent or agent for promoting fluidity is lessand less required, so that the operation is ideal in that the watercontent, necessary at the outset but detrimental at the conclusion ofthe process, progressively diminishes, and eventually becomes so smallthat it may readily be removed by evaporation after the stiff mass isreduced to sheet form by the rolls.

In carrying out my invention, I place the several ingredients in thetrough of a mixing machine of high power, together with only enoughwater to form a stiff, pasty mass. This water content may range as lowas five per cent. It will be obvious that the actual quantity of waterrequired depends upon the character of the materials used in preparingthe adhesive. here desirable, I may employ heat or cold to assist arapid mingling of the substances in the machine. The mass having beenthoroughly mixed by the action of the machine, the product is convertedinto. thin sheets of highly concentrated, nearly dried material. Thismay be accomplished by running the mass through a pair of pressurerolls. The thickness of the sheets may be regulated by adjustment of therolls, or by employing several consecutive pairs of rolls whose spacingprogressively diminishes, which will reduce the sheet to such a slightthickness that evaporation of the remaining moisture con tained in thematerial takes place almost immediately upon exposure to the atmosphere.If desired, the drying of the sheets may be hastened by the employmentof artificial heat; for instance, the sheets may be led from the rollsupon an endless conveyer and passed through a heated chamber, from whichthey will emerge completely dry.

As a-specific example of the operation of my improved process, I placeabout 500 pounds of dry starch, together with onequarter of one percent. of a suitable acid, such as nitric acid or hydrochloric acid, inthe trough of the mixing machine. Heat may be applied to the trough byany suitable means, and the blades then set in motion, whereupon thestarch is converted into soluble starches or deXtrins, the kinddepending upon the temperature and the length of time the starch isexposed to the action of the acid. The required quantity of dextrinshaving been produced, a suitable neutralizing agent, such as ammoniumhydrate, may be used to stop further conversion of the starch. I thenadd a quantity of commercial glucose, approximately seventy-five pounds,together with one pound of phenol crystals, four ounces of oil ofcloves, and only sufficient water to produce a stiff but coherent mass.The necessary quantity of water will vary in accordance with theoperating conditions and the quantity de sired in the finished product.Five to ten per cent. of water based on the total mass mentioned willgive satisfactory results. The blades continue to act upon the severalingredients until they are thoroughly incorporated. When this stage isreached, the product, now in the form of a very stitl mass, is passedthrough suitable rolls or a series of rolls of suflicient power toreduce it to thin sheets, which may be placed upon suitable trays ornets for drying. The quantity of moisture present, however, is so smallthat very little time is consumed in the drying operation. In fact, inthe case when the sheet has been reduced to the minimum practicalthickness, complete evaporation takes place almost immediately uponexposure to the atmosphere. I find it desirable to roll the materialinto sheets which are less than one-eighth of an inch thick. I havefound that a vastly increased production is possible, due to the factthat by employing a minimum of water in the process, only a very smallamount remains to be evaporated. This results in saving an immenseamount of time, expense and space heretofore required for evaporatingthe large quantity of moisture from the films or'layers of adhesivematerials. The use of artificial heat to dry the product issuing fromthe rolls is not necessary in carrying out my improved process, althoughit maybe employed with adhesives which tend to retain their entrappedmoisture.

It will be noted that my invention is not to be limited in any way tothe specific form of apparatus referred to in this specification, nor tothe formation of the particular adhesive described, but on the contraryis of wide application and may be used in many forms, and for theproduction of other adhesives, without departing from the spirit andscope thereof.

Having thus described my invention, I claim:

1. The process of making adhesives which consists in mechanicallycombining the several adhesive ingredients into a concentrated, heavymass capable of being formed into thin sheets, and converting theproduct thus formed into thin sheets.

2. The process of making adhesives which consists in mechanicallycombining the several adhesive ingredients into a concentrated, heavymass capable of being formed into thin sheets, and rolling out theproduct thus formed into thin sheets.

3. The process of making adhesives which consists in mechanicallycombining the adhesive ingredients, adding suiiicient moisture to form astiff, pasty mass, capable of being formed into thin sheets and thenmechanically reducing the product thus formed and while in this stateinto thin sheets.

4. The process of making adhesives which consists in mechanicallycombining dry adhesive ingredients, adding suiiicient moisture to form astiff, pasty homogeneous mass capable of being formed into thin sheetsand then rolling the product thus formed and while in this state intothin sheets.

5. The process of making adhesives which consists in mechanicallycombining the adhesive ingredients in the presence of only suiiicientmoisture to form a. stifi', pasty mass, capable of being formed intothin sheets, mechanically promoting the evaporation of said moisture,and then reducing the product thus formed into thin sheets.

6. The step in the process of making adhesives which consists inmechanically intermingling the adhesive ingredients in the presence ofonly sufiicient moisture to form a stiff, pasty mass, capable of beingformed into sheets.

7. The process of producing adhesives in solid form, consisting inmechanically com bining at atmospheric temperature adhesive ingredientshaving a chemically inert nature with respect to one another into ahomogeneous mass, and mechanically converting the product thus formedinto thin sheets or the like.

8. The process of producing adhesives in solid form, consisting inmechanically combining several adhesive ingredients at atmospherichumidity into a homogeneous mass. and mechanically converting theproduct thus formed into thin sheets or the like.

9. The process of making solid adhesives which consists in mechanicallycombining adhesive ingredients having a substantially chemically inertnature with respect to one another Without substantially raising thetemperature during the combination inthe presence of only sufiicientmoisture to form a stiff pasty homogeneous mass, and then mechanicallyreducing the product thus formed and while in such state into thinsheets or the like.

10. The step in the process of making adhesives which consists inmechanically intermingling, without application of heat, pulverizedadhesive ingredients having a substantially chemically inert nature'withrespect to one another in concentrated homogeneous form with a smallpercentage of moisture but slightly in excess of that desired in thefinished product.

11. The process of making adhesives in solid form from vegetablesubstances having a substantially chemically inert nature with respectto one another consisting in mechanically reducing said ingredients tomiscible condition, mechanically combining the ingredients in suchreduced condition, adding thereto a small amount of moisture, slightlyin excess of the amount that will remain in the finished product,forming the resultant mixture into a stiff and homogeneous mass,reducing said mass to thin sheets or the like, and expelling any excessmoisture therefrom.

12. The process of making adhesives in solid form from vegetablesubstances having relatively chemically inert natures consisting ingrinding said several substances separately to pulverulent condition,adding to one of said substances a small amount of moisture, slightly inexcess of the amount that will remain in the finished product,mechanically combining the several substances into a homogeneous mass,and passing said mass between pressure rolls adapted to expel any excessmoisture therefrom and to reduce said mass to the form of thin sheets orthe like.

WALTER ALEXANDER.

Witnesses:

' Lonn'rro O. TUCKER, MAE R. HARTMANN.

